I define "gravity" in general as the compensating local SPIN 1 vector potential Cartan 1-forms (connections on the co-tangent bundle etc.) that result from locally gauging ALL the UNIVERSAL space-time invariance groups G of all the non-gravity matter field global actions (integrals over the entire history of the observable universe at least).
1005.5052v2.pdf Martin Rees - What is gravity? Can we unify it with the U1xSU2xSU3 fields?
Thanks Jonathan this looks very relevant to what I am doing.
Einstein's equivalence principle ultimately is the UNIVERSAL minimal coupling of G's potentials to the matter fields.
Spin 2 is a composite of entangled pairs of Spin 1. Also there must be Spin 1 and Spin 0 gravity though it might be massive - short-ranged from a Higgs mechanism. The de Sitter extension of the Poincare group including additional dilation and special conformal hyperbolic Rindler horizon boosts must be added.
The vacuum energy density must be a scalar dynamical field /\(x) that when negative on smaller scales is dark matter and that when positive on larger scales is dark energy. That's my answer to "What is gravity?" as a local gauge field in a nutshell.
There are additional aspects such as Wheeler-Feynman holography etc. (e.g. Ibison's paper)
On Jan 7, 2011, at 10:20 AM, Jonathan Post wrote:
Was it this thread that discussed symmetries?
There's a revised version of
http://arxiv.org/PS_cache/arxiv/pdf/1006/1006.1472v5.pdf
The physical meaning of the de Sitter invariants
Ion I. Cot?aescu ∗
West University of Timi¸soara,
V. Parvan Ave. 4, RO-300223 Timi¸soara
January 7, 2011
Abstract
We study the Lie algebras of the covariant representations trans-
forming the matter fields under the de Sitter isometries. We point out
that the Casimir operators of these representations can be written
in closed forms and we deduce how their eigenvalues depend on the
field’s rest energy and spin. For the scalar, vector and Dirac fields,
which have well-defined field equations, we express these eigenvalues
in terms of mass and spin obtaining thus the principal invariants of
the theory of free fields on the de Sitter spacetime. We show that in
the flat limit we recover the corresponding invariants of the Wigner
irreducible representations of the Poincar´e group.
On Wed, Jan 5, 2011 at 6:32 PM, JACK SARFATTI <
Kim
I posted this already yesterday on stardrive science news
I suspect the paper is not right. Ptolemy's epicycles fit the data at the
time pretty well also. However, I have not had time to read it carefully. I
still do not understand the basic picture the author is proposing. However
he cites Martin Rees helping him so I am not ready to dismiss it as crank.
His model seems to dispense with Einstein's GR hence my bias against it.
On Jan 5, 2011, at 6:16 PM, Kim Burrafato wrote:
http://arxiv.org/PS_cache/arxiv/pdf/1005/1005.5052v2.pdf
From the paper's conclusions. Pretty straightforward.
1) The galaxies are attracted to each other by gravity, but there is another
repulsive force which cancels it, perhaps called ”dark energy” or ”the
cosmological constant”. We then need to explain the origin of dark energy
and why it cancels gravity so exactly. This cancellation was apparently
valid when the galaxies were closer together, so dark energy would have to
follow the same inverse square law as gravity. Why does this repulsive force
not show up inside the galaxies? While the observations are indicating zero
force, the evidence for a new hitherto unknown force is perhaps not
compelling.